Wash your jars well. This step can be ideally completed by timing the jars to come out of the dishwasher just as you are ready to ladle the sauce into them so that they’ll be clean and already hot (cold glass can crack or break when receiving hot contents). Cook your tomato sauce as you normally would (see the sidebar if you don’t already have a recipe), omitting meat products (it is riskier and more detailed to can foods with meat int hem, so you can tackle that project when you’re more advanced). You can put in herbs and seasonings or just tomatoes, depending on how you’ll use the sauce. Because we use ours in chili, as spaghetti sauce, as pizza sauce, and in salsa, I use plain tomatoes and add the seasonings after I open the jars. Put the flat lids for the jars into a small pan of boiling water to sterilize them and soften the rubber rims. Start a big kettle (large enough to hold at least one or two jars fully submerged under bubbling water) of water boiling on the stove. Fill each of the hot, clean jars with sauce no higher than where the “shoulders” of the jar become the vertical mouth edges (this air gap is called the headspace). If you have a wide-mouth funnel, use it; otherwise, any spills on the rim or threads of the jar should be wiped off with a clean, damp cloth before lidding. Place a hot lid on top of each cleaned-off jar and screw on the rings, tightening to “finger tight” (a term that always warrants discussion—don’t wrench it tightly, just screw it on as firmly as you would a regular jar lid). When all of the jars are full, place as many as you can into the kettle of boiling water, making sure that the boiling water covers each jar fully. Keep the water at a boil for twenty minutes (boiling time varies depending on the type of food you’re preserving). remove the jars from the bath and let them sit on the counter until cool. When properly sealed, the lids should be sucked down tightly onto the jars. You might hear the telltale “ping” of the suction as the jars cool. Push gently on each lid before you remove the ring to make sure it doesn’t bounce—a properly sealed jar should have a taut, inverted lid. Reprocess each improperly sealed jar, if any, by removing and wiping off the lid, ring, and jar rim; replacing the lid and ring; and boiling the jar for another twenty minutes. Alternatively, you can refrigerate these jars and use their contents within a week. Remove the rings from the properly sealed jars and label them with the month, day, and year. Store them in a cool, dark environment for up to a year (enough time for the next tomato harvest!).

This article was excerpted with permission from the book Urban Farm Projects: Making the Most of Your Money, Space, and Stuff, copyright 2014, I-5 Publishing, LLC. For more budget-friendly and environmentally conscience projects and recipes, pick up a copy today!